This invention is directed to a method of emulsion polymerization and to the enhancement in the rate of emulsion polymer formation. More particularly, a method is provided for the production of emulsions in a new and more efficient manner.
The problem to be solved according to this invention, is the provision of a method of making an emulsion containing a silicone polymer of a high viscosity, in a shorter period of time than is possible with techniques known in the art. Thus, standard techniques of emulsion polymerization, while effective in the production of silicone emulsions, suffer from the disadvantage of yielding suitable emulsions only after periods of time for polymerization which can often be in excess of several days. According to some standard techniques, two to five days can be required to enable the polymerization to proceed, in order that the silicone polymer in the emulsion will reach a desired high viscosity.
This time problem has been solved according to this invention, by the use of a certain unique initiator in the emulsion polymerization technique. These initiators are silanolates and organosilanolates, and the emulsions produced in accordance with the invention contain silicone polymers of equivalent or higher viscosity as standard techniques. Yet, in the present invention, the rate of emulsion polymer formation is achieved in a much shorter period of time, typically in only about three hours. In comparison to the very lengthy periods of time required for emulsion polymer formation under conditions of the standard technique, this is significant.
The silicone emulsions of the invention have been found to be especially useful as additives in the personal care market.